Climate and biogeochemical cycles during the last deglaciation
QUEST-Deglaciation is part of the QUEST programme, Theme 2, funded by NERC. It is a 3-year collaboration between the universities of Bristol, Southampton, Cambridge, Edinburgh, Wales, Oxford and East Anglia, Imperial College London, University College London, and the British Antarctic Survey. The goals of the project are to develop a fuller understanding of what has driven changes in climate, atmospheric composition and biogeochemical cycles during the period from the peak of the last ice age until recent times, and to thoroughly evaluate process-based Earth system model simulations for this period.
The causes of changes in the carbon cycle are poorly understood. Modelled changes in the sources and sink seem to account for the observed LGM methane decrease, but these results cannot be trustworthy evaluated without more detailed knowledge of palaeo-wetlands, palaeo-fire, stable isotopes and vegetation reconstructions. A major aim of QUEST-D is to develop the data synthesis required for testing models of atmospheric composition. This includes extending and creating databases for vegetation, wetlands, fire regimes (from charcoal) and δ13C of vegetation.
Further objectives include development of prognostic models for vegetation, wetlands and fire, and associated emissions of trace gases and aerosols, sea-salt and sulphate-precursor emissions from the ocean, simple forward model of oxygen isotopes of marine carbonate, and a fast atmospheric chemistry model. In the last stage, fast climate models will be used to explore the consequences of changes in external forcing and biogeochemical feedbacks on the transient behaviour of climate from the LGM into the Holocene.